Close encounters between our sun and other stars will be more frequent in some 20 million years, according to a piece in March 1994's Quarterly Journal of the Royal Astronomical Society.
The largest star, during its passage, may well loosen comet nuclei from the Oort Cloud, thought to surround the solar system, and send as many as 100,000 comets our direction.
At least five other stars may pass within between 4.22 and 3.12 light years from the sun, according to the work of Robert Matthews, a visiting fellow at the University of Aston in Birmingham.
While some comets may already be heading our way, they are not expected here for another 20 million years. Time enough, we think, to prepare ourselves for possible doom.